Time Decay Rates of the Micropolar Equations with Zero Angular Viscosity

This paper is concerned with the large time decay rates of the two-dimensional (2D) micropolar equations with zero angular viscosity. Based on the generalized Fourier splitting methods and low frequency effect analysis, we firstly obtain the solutions decay as parallel to u parallel to(L2)+parallel to omega parallel to(L2) <= C(1+t)(-1/2). Moreover, by exploring the new structure of the system, we obtain a new improved decay rates parallel to omega parallel to(L2)+parallel to del u parallel to(L2) <= C(1+t)(-1). Our methods here are also available to the time decay issue of the complex fluid flows with partial dissipation.